After Duke Gozbert converted, Killian explained that the duke‘s marriage with Geilana, his brother’s widow, was unlawful. He secured the duke‘s promise to leave her, which made an enemy of pagan Geilana. She plotted against the saint, and caused the murder of him, Colman and Totnan, and the burial of their corpses, sacred vessels, vestments, and holy writings at the crime scene. When the duke returned to her, Geilana denied knowing the location of the missionaries. The actual murderer went mad, confessed his crime, and died miserably. Geilana herself eventually diedinsane.

Kilian’s good work did not long survive him. When SaintBoniface arrived in Thuringia, he found evidence of his predecessor’s influence. The relics of the martyrs, after cures had brought fame to their burial place, were transferred to the Church of Our Lady in 743 by Saint Burchard, first Bishop of Würzburg. After Burchard obtained Pope Zachary’s permission for their public veneration, they were solemnly transferred, probably on 8 July752, to the newly finished Cathedral of the Saviour. Later they were buried in Saint Kilian’s vault in the new cathedral erected on the spot where tradition says they were martyred. His skull is still preserved, is be-jewelled, and is processed on his feast day. Killian’s copy of the New Testament was preserved in WürzburgCathedral until 1803, and since then has been in the university library.